Spasticity can cause development of contractures, leading to extra physical disability. Spasticity mostly occurs in disorders of the central nervous system, such as spinal cord injury, cerebral palsy, or hemiplegia. The caregivers of spastic patients have to face problems, such as maintaining hygiene and dressing. Otherwise, the ability to stand or walk usually relies on degree of the spasticity. Although, the mechanisms of extracorporeal shock wave therapy (ESWT) on spasticity are still unknown, there are a few studies on this topic in the medical literature. In this study, we described a significant reduction in hypertonia in the plantar flexors after shock wave therapy in patients with spasticity. Fifteen patients (5 males and 4 females) with spasticity were included in the study. The mean age of our patients was 25.6 years. Three patients had hemiplegia, 2 patients had cerebral palsy, and 4 patients had spinal cord injury. Spasticity was upward of than grade II, by modified Ashworth scale (MAS), in all patients. Spasticity was evaluated by MAS from 0 to 4 (0: no spasticity to 4: severe spasticity) on muscles 4 hours after exercises. In each subject, clinical measures were evaluated before and 2 weeks after the ESWT. Rehabilitation sessions varied in length from 30 to 60 minutes. Ankle-foot orthoses were given to all patients; inhibitor hand splint were used in patients with hemiplegia. ESWT was planned for reduction of spasticity, improving compliance with an exercise program. Reduction in physical activities in patients with spasticity leads to low endurance, deconditioning increased heart rates and energy costs. ESWT was applied in the first week of physiotherapy sessions every other day, 3 sessions in total. Rehabilitation programs continued after ESWT. Shock wave therapy instrument BTL® -5000 Power was used for ESWT. The pressure pulses were focused on the spastic side of upper and lower muscles. Shots (2000) were given in the belly of the muscles, and the intensity was 0.1 mJ/mm2 (2 bars).